Construction of P/Ag@AgCo PBA hollow cuboid and its bifunctional activity for water splitting

Silver (Ag) and phosphorus (P) doping have been demonstrated to optimize electron density, enhance conductivity, and accelerate electron transfer. Moreover, construction of hollow structures can expose more active sites, significantly improving the performance of catalysts. Therefore, developing P/Ag-doped hollow structures for water splitting is highly promising and meaningful. However, similar studies remain rarely reported. In this work, we designed and synthesized a P-doped Ag 3 [Co(CN) 6 ] hollow cuboid, named as P/Ag@AgCo PBA, aiming to develop an efficient and high-performance water splitting catalyst. Benefiting from its hollow structure and P/Ag co-doping, the optimized P/Ag@AgCo PBA-1 exhibited outstanding catalytic activity. • In the hydrogen evolution reaction (HER), it achieved a current density of 10 mA cm −2 at a low overpotential (η 10 ) of 117 mV with a Tafel slope of 43.6 mV dec −1 . • In the oxygen evolution reaction (OER), the η 10 was 253 mV, and the Tafel slope was 65.3 mV dec −1 . • In the hydrogen evolution reaction (HER), it achieved a current density of 10 mA cm −2 at a low overpotential (η 10 ) of 117 mV with a Tafel slope of 43.6 mV dec −1 . • In the oxygen evolution reaction (OER), the η 10 was 253 mV, and the Tafel slope was 65.3 mV dec −1 . Owing to its excellent HER and OER performance, when employed as both the cathode and anode in overall water splitting, the catalyst required only 1.66 V to reach a current density of 10 mA cm −2 . Furthermore, it demonstrated remarkable catalytic stability over 24 h of continuous operation. We believe this facile and effective etching and heteroatom co-doping strategy offers new opportunities for the development of similar high-performance water splitting catalysts.